Look at the calendar. That far along in the year already? It seems only yesterday when your organization started January with a twinkling sense of optimism and a strategic plan that laid out the next 12 months with military precision.

But if your organization is like many, your strategic plan may now seem to have all the worth and relevance of a well-intended but hastily drawn list of New Year’s resolutions. There are the usual reasons for this:

You’ve had no routine check-ins to make stakeholders accountable for meeting goals

But most likely there is another reason: The world your team saw at the end of last year already looks different this year. Some shifting has occurred—perhaps in the market, or with internal personnel or other distractions, or maybe in the national economic or political situation or in technology. Today you know things you didn’t or couldn’t have known then.

It’s okay. Shifts happen.

The fact that the world changes, sometimes dramatically, in just a few months is no reason not to have a well-done annual strategic plan. In fact, it’s exactly why having one is so important: knowing what the organization intended at the beginning of the year makes it easier to identify and adjust for the deltas that occur. Having a plan exposes what’s not in the plan.

Dealing with minor interruptions and big black swans takes time and resources from what you thought you’d be doing. Having a strategic roadmap, with clearly defined milestones, makes it easier to determine what trade-offs are needed to adjust. To make the job easier still, try to align each goal with resources and level-of-effort estimates.

In agile methodology, work teams are managed based on their finite capacity. Each job is given some kind of scoring, or weighting, to determine its level of effort relative to others. Most likely, the sum of all the sizings will exceed the available resource capacity to do the work. This forces prioritizing: Whatever doesn’t make it into the release schedule ends up in the backlog. To prioritize the backlog, you can rank the relative business value as well as the cost of delaying the job.

Imagine having a strategic plan where each goal is weighted relative to the others, and job size and cost of delay are mapped in advance. It would be so much easier to deal with the headwinds of new developments and make trade-offs to best utilize limited organizational capacity.

A well-constructed plan can also protect an organization from avoidable headwinds, such as when an influential board member or executive tries to muscle through a request that threatens to throw the enterprise off its plan. A defensible process for establishing and vetting priorities might just impress and inspire the Big Foot to play by the rules.

Shifts will always hit the fan. Or, as John Lennon more artfully sang: “Life is what happens when you’re busy making other plans.”

But a well-drawn strategic agenda, with SMART goals and clearly articulated levels of effort, can limit over-reactions and keep the organization moving forward.